Technological Field
The present invention relates to an image forming apparatus and a life judgment system which manage the replacement timing of the replacement part. Further, the present invention relates to an image forming apparatus which changes the fixing control parameter relating to the fixing of the image.
Description of the Related Art
In a device installed in an office or the like, such as a multi function peripheral having a copy function, a scan function, a print function and the like, in case that the part of the device is replaced after the lifetime of the part is ended and the part is ordered, it is inconvenient for a user to be unable to use the device for a long time. Therefore, the regular report indicating the usage amount and the like of each replacement part is regularly transmitted to a maintenance management device of the maintenance company via a network, and the replacement timing of each part is estimated by the maintenance management device. Before the lifetime of the part is ended, a new part is sent or the part is replaced with a new part by a serviceperson.
However, it is difficult to accurately estimate the lifetime of each part only by using the regular report. For example, the lifetime of each main member (a pair of rollers, a belt and a driving unit) used in the fixing device is generally judged in accordance with the operation time and the number of paper sheets used in the printing. In the PP (Production Printer) machine or the like, because the used conditions (the type of paper sheet, the size of paper sheet, the continuous operation and the like) are varied, the dispersion of the lifetime which is conventionally judged in accordance with the operation time and the number of paper sheets used in the printing becomes large.
Further, because the allowable range of the image quality is varied according to the users, it is difficult to uniformly judge the lifetime of the part in accordance with the conventional standard, such as the operation time, the number of paper sheets used in the printing, and the like.
In particular, the so-called gloss memory which is the phenomenon that the wax is moved from the toner image to the fixing members (rollers/belt) and is transferred to another image after one rotation of the belt, is gradually caused due to the degradation of the roughness of the surface of the fixing member. However, according to the type of paper sheet, the level of the actualization of the above phenomenon is varied. Even if the above phenomenon is caused, the visibility of the above phenomenon is varied according to the contents of the image. Further, the visibility of the above phenomenon is varied according to the users. From the above-described reasons, in accordance with the conventional standard, such as the operation time, the number of paper sheets used in the printing, and the like, it is difficult to judge whether the gloss memory is caused at the level in which there is some possibility that a complaint is made by the user (at the level in which the lifetime of the member is ended).
In Japanese Patent Application Publication No. 2016-206635, the technology for directly detecting the roughness of the surface of the fixing member by using the optical sensor is disclosed.
In Japanese Patent Application Publication No. 2016-206635, because the portion of the fixing member, which corresponds to the edge portion of the paper sheet is repaired, the roughness of the surface of the fixing member is detected at only a part of the fixing member (at the edge position of the paper sheet having the specified size) by the optical sensor. On the other hand, in order to judge the degree of the degradation of the fixing member due to the gloss memory, it is necessary to detect the roughness of the surface of the fixing member in the overall width of the fixing member. In case that the roughness is detected by using the method disclosed in Japanese Patent Application Publication No. 2016-206635, it is necessary to dispose many sensors or to have the structure for scanning the fixing member in the overall width thereof. However, because the optical sensor has the low durability to a high temperature, it is practically difficult to detect the roughness of the surface of the fixing member in the overall width thereof when the temperature of the fixing member is high.
Therefore, it is preferable to detect the change in the surface condition of the fixing member by using only the usual mechanism without adding the special mechanism, such as the optical sensors or the like.
Further, in the conventional method and the method disclosed in Japanese Patent Application Publication No. 2016-206635, because it is not possible to detect the degradation condition of the fixing member at a high accuracy, it is difficult to execute the process in which it is necessary to grasp the accurate degradation condition, for example, the process for changing the fixing control parameter used in the fixing step of the image forming in accordance with the degradation condition of the fixing member.